Torque controlled strand tensioning system and method



0. E. HEIBERG Jan. 2, 1962 TORQUE CONTROLLED STRAND TENSIONING SYSTEMAND METHOD 4 Sheets-Sheet 1 Filed Dec.

we T E Na We N IE F m N E E O 3; 1 ATTORNEYS Jan. 2, 1962 Filed Dec. 11,1959 I O. E. HEIBERG TORQUE CONTROLLED STRAND TENSIONING SYSTEM ANDMETHOD 4 Sheets-Sheet 2 ZNVENTOR.

OERNULF E. Heasewacr ATTORNEYS 0. E. HEIBERG Jan. 2, 1962 TORQUECONTROLLED STRAND TENSIONING SYSTEM AND METHOD 4 Sheets-Sheet 3 FiledDec.

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INVENTOR: OEQNULF E. Ha BERG- BYaj'm,bil1A&mC}4W ATTORNEYS 0. E. HEIBERGJan. 2, 1962 TORQUE CONTROLLED STRAND TENSIONING SYSTEM AND METHOD 4Sheets-Sheet 4 Filed Dec.

INVENTOR: OERNULF- E. Henseae- BY ahfimM R ATTORNEYS United StatesPatent Office 3,015,203 Patented Jan. 2, 1962 3,0153% TQRQUE CGNTRGLLEDSTRAND TENEEEGNTNG dYSTEll/f AND METHUD Oernulf E. Heiherg,Charlottesville, Va, assignor to Whitin Machine Worlrs, Whitinsville,Masa, a corporation of Massachusetts Filed Dec. 11, 1959, Ser. No.S59,tl47 47 Claims. (Cl. 57-93) This invention relates to a novelapparatus and method for controlling tension in textile strands fed torotating carriers or bobbins by a relatively rotating feeding ele ment.More particularly, the invention relates to a novel apparatus and methodfor maintaining predetermined uniform winding tension in roving orsimilar fibrous strands, coiled onto rotating bobbins or spools byrelatively rotating flyers on roving frames, intermediates, slubbers andthe like.

It is well known that a strand of roving normally contains just enoughtwist to keep the fibers together, and is, consequently, a loosestructure of low strength. Exposed to longitudinal tension, a rovingstretches to a sometimes considerable extent, varying with the amount oftension, with the radius of curvature of the surface which may besupporting the roving, and with other factors. As a suitable measure ofthis elongation, the stretch factor (7) may be defined as the ratio of alength of roving on the bobbin to the corresponding length delivered bythe front drafting rolls of the roving frame.

Since the variations in the stretch factor inversely representvariations in the weight per unit length of the roving and,consequently, of the yarn spun from the roving, it is of utmostimportance from a manufacturing viewpoint to maintain the smallestpossible stretch factor variation in the strand as it is being wound onthe bobbin. This is the primary object of the present invention.

Roving strands are wound on rotating bobbins by means of flyers rotatingat lesser speed than the bobbins, the traversing of the strands onto thebobbins usually being effected by vertical reciprocation of the bobbins.The coils of roving thus wound on to the bobbin form cylindrical layers.The term lay spacing refers to the center'to-center distance between anytwo adjacent coils along the length of the bobbin, and is usuallyexpressed in coils per inch. The lay speed is the linear velocity,usually expressed in inches per minute, of the vertical movement of thebobbin carriage. Since the flyers do not move either up or down, the layspeed is also the traversing velocity of the bobbins relative to thefiyers. The term r.p.m. as used hereinafter means revolutions perminute. The difference between the bobbin r.p.m. and the fiyer r.p.m.may be referred to as the winding r.p.m.

During a run or winding cycle, the fiver usuallv rotates at a constantr.p.m., while the diameter of the bobbin increases step by step witheach add'tiona] layer of roving. To take the roving up at a constantrate as it emerges from the front drafting rolls, it thus becomesnecessary to stepwise decrease the bobbin r.p.m. in such a manner thatthe winding r.p.m. will vary inversely to the momentary diameter of thebobbin. The decrease in winding r.p.m. is conventionally effectedthrough the use of a pair of oppositely tapered cone pu leys, with abelt connecting them. One of the cone pulleys, usually the top cone, isdriven at a constant r.p.m. The other cone pulley, usually the bottomcone, rotates at a gradually decreasing r.p.m., achieved by stepwiseshifting of the belt.

The variation of the winding r.p.m. has heretofore taken place accordingto a mechanically predetermined program through the elements involved indriving the bobbins. Due to its inherent rigidity, such a system cannottake into account the many pertinent variables, such as the elasticproperties of the fibers, the density of the package, the hank number,the condition of the ambient air, etc. A given pair of cone pulleys cantherefore, in principle, be accurate only for a given set of thesevariables, and will otherwise be more or less inaccurate. As the conepulleys are actually manufactured, their curvature is nearly alwayssignificantly inaccurate. The usual system of controlling the stretchfactor of the roving by varying the winding r.p.m. stepwise during therun according to a predetermined program, is susceptible also tovariations depending upon the judgment of the operating personnel. Inmany mills, the operators choose a starting point for the cone belttravel, which, unknown to them, causes the first few hundred yards ofroving deposited on each bobbin to be as much as five to ten percentlighter than the average of subsequent lengths.

The variation in the weight of the roving resulting from theinaccuracies of the conventional roving frame adds materially to thecost of the yarn manufacturing process and tends to produce inferiorproducts. The heavier sections of the roving may result in a waste ofmaterials. The lighter sections tend to increase the amount of twistneeded in the subsequent spinning opstation. The irregularities in theweight of the yarn frequently detracts from the commercial value of thefinal fabric.

In order to overcome the above-mentioned and other defects ofconventional roving frames, it is an object of this invention to providea novel method and apparatus for accurately controlling the stretchfactor, which is effected by accurate control of the winding tension;i.e., the tension in the roving between the presserfoot of the fiyer orflyers and the bobbin or bobbins, this control being effected by sensingand regulating the torque transmitted from the bobbin or bobbins throughthe roving to the fiyer or flyers.

A preferred embodiment of apparatus for controlling the winding tensionaccording to the present invention comprises a variable speed drive orwinding speed variator, which may replace the conventional cone pulleys,and the output portion of which is connected to one of the two inlets ofa conventional differential gear assembly, commonly known as a compound.The other inlet is driven by the main drive shaft, and the output of thecompound drives the bobbins, as is well known. An auxiliary drive shaft,driven at a speed directly proportional to the speed of the main driveshaft, drives the input shaft of the variator at a constant r.p.m.through the medium of a torque balancing device which senses the torqueof the input shaft of the variator and to which a predetermined, orcontrolled, external torque is applied. Since the torque in both theauxiliary shaft and the variator input shaft must remain equal, upon anytendency for the torque of the input shaft to vary, because the windingr.p.m. is such that the winding tension is not maintained at itsprescribed value, the torque balancing device effects a change in theoutput speed of the variator sufficient to equalize the torque in thevariator input shaft and the auxiliary shaft, and, thus, sufficient toproduce a winding r.p.m. maintaining the winding tension at itsprescribed value.

Although my new system for control of the winding tension may be used inconjunction with the conventional cone drive, it is contemplated thatthe usual cone pulleys may be eliminated and replaced by theaforementioned winding speed variator. The coils per inch of roving onthe bobbin (lay spacing) are always equal to the ratio of the windingrip.m. to the linear traversing velocity (expressed in inches perminute) of the bobbin carriage. On the conventional roving frame, thisratio is usually constant, because both the winding rpm. and thevelocity of the bobbin carriage are derived from the conventionalvariable speed cone pulley; i.e., the bottom cone shaft.

It is therefore another object of this invention to provide a novelmethod and means for varying the coils per inch during the run in anydesired ratio to the winding r.p.m. A preferred embodiment of means forvarying the coils per inch during the run comprises a second variablespeed drive or lay speed variator for imparting traversing movement tothe bobbin carriage whereby the ratio between the winding rpm. and thetraversing velocity of the bobbin carriage may or may not be keptconstant during the run. The two variators may be con trolled together,both actuated by the torque balancing device, but not necessarilyaccording to the same program. By suitably interconnecting the controlscrews of the two variators, it is possible to vary the coils per inchduring the run in any manner to suit the individual case.

A progressive reduction in the number of coils per inch during the runtends to provide the conical end surfaces of the bobbin with a moreconvex contour than is normally the case. The volume of each bobbin maythereby be increased and the tendency for the roving to slough off overthe top of the bobbin near the end of the run, which otherwise mightprevail, may be obviated.

Some of the objects of the invention having been stated, other objectswill appear as the description proceeds when taken in connection withthe accompanying drawings, in which FIGURE 1 is a diagram of a systemfor controlling the bobbin r.p.m. of a roving frame or similar machinerelative to the flyer rpm. in response to variation in winding tension,and for correlating the speed of the traverse motion, in accordance withthe present invention;

FIGURE 2 is an enlarged somewhat schematic view of the structure shownin the lower central portion of FIG- URE l, presenting the speedvariators in greater detail and showing the torque balancing devicepartly in section;

FIGURE 3 is a schematic electrical diagram, includin means for lockingthe housing of the torque balancing device while the machine is idle,for the purpose of effectively preventing its rotation;

FIGURE 4 is a fragmentary detail of a bobbin, bolster, spindle, flyerand associated gears similar to that shown in the left-hand centralportion of FIGURE 1, the elements of FIGURE 4 being representative of aplurality of such elements of a roving frame:

FIGURES 5 and 6 are schematic diagrams illustrating the relativepositions of the presserfoot of the flyer with packages of differentdiameter;

FIGURE 7 is an enlar ed longitudinal sectional view through adifferential compound illustrative of that shown in the left-hand upperportion of FIGURE 1;

FIGURE 8 is an enlarged fragmentary elevation, partially in section,taken substantially along line 8-8 in FIGURE 2 and showing an overridingclutch mechanism between the auxiliary drive shaft and one of a pair ofsprocket wheels mounted thereon;

FIGURE 9 is a fragmentary sectional view taken sub stantially along line99 in FIGURE 8;

FIGURE 10 is a View similar to FIGURE 8 taken substantially along line101@ in FIGURE 2;

FIGURE 11 is a view similar to FIGURE 3 taken substantially along line11-11 in FIGURE 2;

FIGURE 12 is a view similar to FIGURE 2, but showing a modifiedarrangement for controlling the lay speed variator in relation to thewinding speed variator.

General synopsis of the invention As heretofore stated, the stretchfactor and winding tension in the roving are accurately controlled,according to the present invention, by sensing and regulating the torquetransmitted from the bobbin through the roving to the flyer. In order tomaintain a constant stretch factor, the winding tension must either bekept constant during the run or it must be made to vary in apredetermined manner. In order that the winding tension is maintainedconstant, the torque transmitted from the bobbin to the fiyer throughthe roving must increase in direct proportion to the bobbin diameter.

Since, as mentioned above, the winding r.p.m. varies inversely to thebobbin diameter, the product of the winding torque and the winding rpm.is independent of the diameter, and consequently remains invariantduring the run if the winding tension is constant. The product of thewinding torque and the Winding r.p.rn. represents the power, expressiblein watts or horsepower, consumed in the actual winding of the roving onthe bobbin 31. This product may therefore be referred to as the windingpower (Ev).

The winding power, being determined by the tension under which theroving R (FIGURE 1) is being wound on the bobbin 31 and also by the rateat which it is taken up, is essentially independent of the mechanismemployed. An accurate theoretical analysis, as applied to theconventional roving frame, leads to the formula:

wherein Ev is the total winding power for the whole machine expressed inhorsepower units (1 hp.746 watts); for a roving frame with m spindles;the roving is being wound on the bobbins under a tension of W grams; thediameter of the front bottom drafting roll is d inches; this rollrotates at the constant rate of 1' rpm; and the stretch factor is f.

Equation I shows that, assuming the stretch factor (f) to be constant;the winding tension (W) and the winding power (Ev) are strictlyproportional, one to the other. Constancy of either of these twoquantities depends on constancy of the other.

On the conventional roving frame, the traversing motion of the bobbincarriage is driven from the variable speed cone pulley, i.e., from thebottom cone shaft. The same shaft is also connected to one of the twoinlets of a differential gear assembly, commonly referred to as thecompound. The output of the compound drives the bobbins. The gear ratiosare usually chosen so that the cone pulleys provide the winding r.p.m. Acomponent of the bobbin r.p.m., equal to the flyer rpm, is introduceddirectly from the main shaft of the machine into the compound throughthe second of the two inlets. Since all the winding motion comes fromthe cone drive, the winding r.p.m. will be zero if the cone drive isdisconnected. The bobbin r.p.m. will in that case be equal to the flyerrpm, and no winding will take place.

Referring to the conventional roving frame as described above, thepreferred apparatus for carrying out the invention can make use of avariable speed drive of any of the known types, instead of theconventional cone pulleys. For the purpose of brevity, such a variablespeed drive may be termed as a variator. Since I wish to reserve onevariator 1125 exclusively for the transmission of the winding power, asecond variator 245 is needed to transmit the power for the traversemotion. As heretofore stated, the two variators are termed as thewinding speed variator and the lay speed variator, respectively.

Disregarding frictions, the winding speed variator transmits nothing butthe winding power. From what already has been said, it may be understoodthat the winding tension under those conditions will be strictlyproportional to the power transmitted by the winding aoiaaoa speedvariator 125. The winding tension will remain constant if thetransmitting power is constant.

If frictions again are disregarded, the power transmitted by the windingspeed variator 125 will be equal to the rpm. of the input shaft 132 ofthe variator 125 multiplied by the torque in the same shaft. Since theinput shaft 132 of the winding speed variator 125 ro tates at a constantr.p.m., we finally arrive at the conclusion that the total windingtension for all the bobbins 31 on the frame will be strictlyproportional to the torque transmitted by the input shaft 132 of theWinding speed variator 125. The average Winding tension on each bobbin21 may therefore be kept constant, or it may be varied during the runaccording to any prescribed program, by corresponding control of thetorque transmitted by the input shaft 132 of the winding speed variator125.

The torque of the input shaft of the winding speed variator may besensed or measured by transmitting it through a device which I shallrefer to as a torque balancer, torque sensing device, or torquemeasuring device 131 (FIGURES 1 and 2).

The winding speed variator 125 is shown to the left in FIGURE 2. Thepower input passes from left to right through the torque balancer 131,consisting of a simple bevel gear differential assembly shown in themiddle of FIGURE 2. The planetary bevel gear 150 rotates on the stubshaft 147 attached to an external housing 133, held essentiallystationary by the application of a controlled external torque. Thetorque needed to prevent rotation of the housing 133 is exactly twicethe torque transmitted from right to left through the differential gearassembly. An accurate analysis shows that the torque in gram-incheswhich must be applied to the torque balancer housing to prevent itsrotation is where, as in Equation 1, W is the winding tension in gramsfor each individual bobbin; d is the diameter in inches of the frontbottom drafting roll; m is the number of spindles on the frame, and f isthe stretch factor. F is the constant ratiofixed by the permanentgearing of the machineof the rpm. of the front bottom drafting roll tothe rpm. of the input shaft 132 of the winding speed variator 125.

In Equation II, F, d, and m are constants, because their values havebeen built into the machine. The stretch factor f may be assumed to beat least approximately constant. Equation'II therefore shows that theaverage winding tension (W) for each bobbin and the external controltorque (Q which must be applied to the torque balancer housing toprevent its rotation, are proportional one to the other, and that thefixed ratio between these two quantities can be accurately predeterminedby calculations based on the gearing of the machine.

The controlled external torque (Q applicable to the torque balancerhousing 133 to prevent its rotation, may in principle be provided bymeans of a weight B suspended by a string 151 wrapped around a drum 152attached to the torque balancer housing 133. The drum may, or may not,be cylindrical. To produce a programmed variation of the Winding tensionduring the run, the leverage upon which the weight B is acting may bemade to change during the run, for example by letting the string followa spur in a non-cylindrical drum. Or, there may be two drums ofdifferent shape, each with its own weight and string, and the other tocompensate for the torques resulting from friction. The controlledtorque may also be obtained by springs, or by electrical, h draulic orpneumatic means, without departing from the spirit of the invention.

If the torque passing from the right to left through the torque balancermomentarily should exceed the value determined by the external controltorque, for example, because the winding rpm. is slightly too high tomaintain the winding tension at its prescribed value, then the torquebalancer housing 133 with the drum attached to it will turn in such adirection that the weight B is raised. The rotation of the housing istransferred to the control shaft 143 of the winding speed variator insuch a direction that the output shaft 124- of the variator is made toslow down enough to bring the torque passing through the torque balancerback to its prescribed value, and thereby reestablish equilibrium.

Detaiz'ed description Referring more specifically to the drawings, andto FIGURE 1 in particular, an apparatus for carrying out the method ofthe present invention is shown in association with a conventionalcompound for the bobbin drive and a conventional traverse motion of aroving frame, ail of the parts being shown somewhat schematically in adiagram of Well-known form. With the exception of the particularelements of the present invention, the illustration of FEGURE 1corresponds to a roving frame of the type manufactured by a well-knownAmerican textile machinery manufacturer, but roving frames made by othermachinery builders are not essentially different. The illustration ofFIGURE 1 is similar to illustrations provided in many catalogues andinstruction booklets issued by the manufacturers of roving frames andwhich are well-known in most textile mills. Thus, the conventionalelements illustrated in FIGURE 1 may be readily recognized by thosefamilar with the art.

Referring to FIGURE 1 more in detail, the numeral lit indicates the maindrive shaft of the roving frame which has a pulley 11 thereon driven byan electric motor 12 through the medium of an endless belt 13 and apulley id fixed on the shaft of the motor 12. Drive shaft I10 has a geari5 fixed thereon which is connected, by a diagrammatically illustratedgear train 16, to a gear 17 fixed on a spindle haft Zii. Spindle shaft26 drives a plurality of conventoinal spindles 21 on each of which ismounted a strand traversing means embodied in a fiyer .22. Only one ofthe spindles 2?. and fiyers 22 are shown in the drawings, although it iswell-known that a plurality of such spindles and fiyers are provided oneach machine.

Spindle shaft 29 imparts rotation to each spindle 21 by means of beveledgears 23 and 24. Roving or a similar strand of textile strand material Ris fed to each fiyer 22 from the usual drafting rolls D. As shown inFIG- URE 4-, the strand R passes through an opening 25 in the upper endof the flyer 22, then passes partially around said upper end of theflyer and through one of its arms 26, which arm is hollow, as is usual.The roving strand R then passes out of the iower end of the hollow arm26 and passes around the conventional presser finger 27 and then throughthe usual opening provided in the presserfoot or paddle 28 to be woundin the form of coils around an axially reciprocal carrier or bobbin 31.

Each bobbin or carrier 31 is positioned on a bolster or other support 32having a gear 33 on its lower end which rests upon a bracket 3 (FIGURE4) carried by the conventional bolster rail 35. The bolster rail 35,frequently called the bobbin carriage, is common to all the spindles andbolsters on the machine. Each gear 3-3 meshes with a bevel gear 3-6fixed on a bobbin shaft 37 which is also common to all the spindles andbolsters on the machine. Bobbin shaft 3'7 is connected to the outputportion of a conventional differential compound, broadly designated atA9, by means of gears 41 and 42 and an intervening gear train 53. Thedifferential compound 40 is conventional and is mounted on the maindrive shaft in as will be later described in more detail.

The constant speed main drive shaft lit opposite from drive pulley lllhas a direct drive connection to the top cone shaft 50 which issubstituted for the usual top cone shaft, or the usual top cone shaftmay be used in this instance. For purposes of clarity hereinafter, theshaft will be termed as the top cone shaft, although the usual top conemay be omitted. A twist change gear 4-5 fixed on main shaft 14 is one ofa plurality of gears forming a gear train, generally designated at 46.The twist gear train also includes a gear 47 fixed on top cone shaft 50.

The direct drive is also transmitted through gears 48, 49 to the frontroll shaft 4%, and thereby to the drafting rolls D. Top cone shaft '1)also imparts intermittent rotation to contact 51, sometimes called atumbler shaft, which is a part of the conventional rack mechanism 52.and is instrumental in reversing the direction of traverse of bolsterrail 35 and bobbins 31. The conventional rack mechanism 52 is shown inpart in FIGURE 1. However, the usual belt shifter may be omitted fromthe rack mechanism, since it is not required with the illustratedembodiment of the present invention.

The bobbins 31 are raised and lowered by means of a conventionaltraverse motion, certain elements of which will now be described. Atraverse drive shaft 55 (PI URES 1 and 2) may be driven by meanspeculiar to the present invention and which will be later described.Traverse drive shaft 55 has a bevel gear 56 fixed thereon which isalternately engaged by a pair of spaced twin bevel gears 57, 58. Gears57, 58 are fixed on a common. sleeve 6% keyed for axial movement on anauxiliary traverse drive shaft 61.

Auxiliary traverse drive shaft 61 has a bevel gear 62 fixed thereonwhich meshes with a bevel gear 63 fixed on a jack shaft 64. Shaft 64also has a spur gear 65 fixed thereon which meshes with a gear 66 fixedon a lay shaft 67. Lay shaft 67 has a lay change gear 71 fixed thereonwhich meshes with one of a lay train of gears generally designated at'72. The lay train 72 also includes a gear 73 which is fixed on aconventional lifter shaft 74 having one or more pinions 75 fixedthereon, each of which meshes with an arcuate lift rack 7'6 which isformed integral with a bobbin lifter arm '77. Through conventionalmeans, not shown, the lifter arm 77 is connected with bolster rail 35for imparting vertical reciprocation thereto.

As is well known, twin gears 57, 58 are alternately shifted intoengagement with cone gear 56 on the traverse drive shaft 55 by means ofreversing lever se. Lever 811 is shifted to and fro by means of aneccentric cam 81 fixed on the lower end of contact shaft 51. Contactshaft 51 has a dog 82 fixed thereon which is provided with a pair ofvertically spaced and oppositely directed arms or abutments 83, 84 whichalternately engage a pair of interconnected, but relatively adjustablebuilder jaws 85, 86 which are guided against a stationary plate 87 andare penetrated by respective oppositely threaded portions of a builderscrew 90. Builder jaws 85, 86 are raised and lowered with bolster rail35 (FIGURE 4).

As builder jaw 86 moves below and out of engagement with the upperabutment 84. on builder dog 82, conven tional resilient means, notshown, but associated with cam 81, causes the teeth of a missing-toothgear 11, on the upper end of contact shaft 51, to engage a bevel gear 92fixed on top cone shaft 511. Since top cone shaft 50 and bevel gear 92are continuously driven during each winding cycle, a half revolution isimparted to shaft 51 to cause the other arm or abutment 83 of builderdog 82 to engage builder jaws 85, 86 as an area of missing teeth on gear91 registers with gear 92. In so doing, the eccentric cam 31 in thelower right-hand portion of FIG- URE 1 moves reversing lever 80 andshifts sleeve as and gears 57, 53 in the corresponding direction, thusreversing the direction of movement of bobbin carriage 35. Thisprocedure is reversed as the bottom builder jaw 85 moves above the levelof the abutment 33 on the builder dog 82.

In order to vary the displacement between the distal surfaces of thebuilder jaws 85, 8d and to, consequently, vary the length of stroke ofthe traverse of the bobbin rail 35 and the bobbin 31, the builder screw90 is rotated in a stepwise manner, each time a half revolution isimparted to builder dog 82 in the manner heretofore described. Theconventional rack mechanism 52 is used for this purpose, and it will benoted that contact shaft 51 has a worm 95 fixed thereon which mesheswith a worm gear 96 connected through a gear train 97 to a rack 102.

Rack 102 is engaged by a pinion 183 having another pinion 16 i integraltherewith, or connected thereto, which meshes with a gear 1G5 keyed onthe upper portion of builder screw 90 so the builder screw 91 may movevertically relative to the gear 105. It is apparent that, each time astep in rotation is imparted to contact shaft 51, a step in movement isimparted to rack 102 to thus impart a step in rotation to builder screw90 and to thus move builder jaws 85, 86 toward each other at the end ofeach stroke of bobbin carriage 35 (FIGURE 4) in each direction. A handwheel 106 is usually provided on the upper end of builder screw 90 forresetting builder jaws 85, 36 at the end of each winding cycle or run.

Difierential compound Although the differential compound 40 is notpeculiar to the present invention, it will now be described in detail inorder that the invention may be clearly understood. Generally, thecompound performs an addition of a variable r.p.m. component derivedfrom the bottom cone shaft and a constant rpm. component coming directlyfrom the main shaft 10 of the frame, making the sum of the twocomponents available for the drive of the bobbins. The gear ratios areusually selected so that the variable r.p.m. component provides thewinding rpm, and the constant r.p.m. component provides a component ofthe bobbin r.p.m. equal to the flyer rpm.

The differential compound 40 is best shown in FIG- URES 1 and 7 whereinit will be observed that it comprises a housing 110 (first or constantspeed input element) fixed on main shaft 10 and provided with aninternal or ring gear 111 which is engaged by a planetary gear 112. Theplanetary gear 112 also engages a sun gear or sleeve gear 113 fixed onthe inner end of an inner sleeve 114 (second or variable speed inputelement) loosely journaled on the main shaft 10. Another outer sleeve115 (variable speed output element) is loosely journaled in the sleeve114 and has a pair of diametrically opposed arms 116, 117 extendingtherefrom. Planetary gear 112 is journaled on arm 116 and acounterweight 12-9 is journaled or fixed on the other arm 117. The speedof output sleeve 115 may be calculated by the formula:

where,

n =r.p.m. of outer sleeve 115 n =r.p.m. of sun gear 113 and inner sleeve114 M=r.p.m. of internal gear 111 t =Number of teeth in sun gear 113 iNumber of teeth in internal gear 111 Gear 42, described heretofore, isfixed on the outer portion of outer sleeve 115 and another gear 121 isfixed on the outer portion of inner sleeve 114. Gear 121 is connected,by a gear train 122, to a gear 123 (FIGURE 1) fixed on the output shaft124 of the winding speed variator broadly designated at 125, and whichconstitutes one of the most important elements of the present invention.The output shaft 124 may be termed as an intermediate bobbin driveshaft. Shaft 124 may be continuous, but is shown in the form of twointerconnected sections 12 1a, 12% for purposes to be later described.

It might be stated that conventional roving frames are usually providedwith a common shaft extending from the traverse reversing bevel gear 56to gear 123, and the equivalent of shaft 124 is then driven by the usualbottom cone. In effect, therefore, the winding speed variator 125 Torquecontrolled bobbin drive and tension regulator An accurate analysis ofthe interaction of the various parts of the conventional roving frameleads to the following exact equation:

where,

D=Effective winding diameter of the bobbin at any given layer of roving,

R Momentary ratio of the bottom cone r.p.m. to the top cone r.p.m.,

f=ivlomentary value of the stretch factor,

K specific constant for the individual roving frame, de-

rivable from the gearing.

Although the variations in the value of the stretch factor (f) are veryimportant, they are relatively small. Equation IV therefore shows thatthe bobbin diameter (D) is essentially determined by the cone driveratio (R).

Due to the difference in radial pressure, the fiber material nearest tothe core of the bobbin is usually more compressed than that in the outerlayers. A bobbin where the stretch factor has exactly the same value inevery yard of roving, may be referred to a a perfect" bobbin. if, by anymeans at all, such a bobbin had been made, an analysis of it would showthe density of the fiber material to decrease from the inside to theoutside of the bobbin according to some definite mathematical law.Conversely, the conventional roving frame will only produce a perfectbobbin if the cone drive controls the diameter increase according to aprogram that reproduces the law governing the density distribution in aperfect bobbin.

This law, unfortunately, differs with the density level, with theelastic propertie of the fiber material, and with other variables. in nocase, is it accurately known. A given pair of conventional cone pulleyscan therefore in principle be accurate only for a given set of thepertinent variables, and will otherwise be more or less inaccurate. Asactually manufactured, the cone drives are significantly inaccurate, andmay differ considerably between any two presumably identical machines.

The conventional means for controlling the stretch factor of the rovingare therefore unsatisfactory, both because they never are entirelyaccurate and also because they lack the flexibility necessary to adaptthemselves antornatically to differing conditions.

According to the present invention the stretch factor of the roving iscontrolled, not by a pre-set program of relative speeds, but throughcontrol of the winding tension. As far as is known, a bobbin wound underconstant winding tension will be perfect in the sense that the stretchfactor will have the same value for every yard of roving on the bobbin.Even if more refined measurements sometime in the future should showthat this is not always entirely accurate, a slight gradual change inthe winding tension may be effected to keep the stretch factor constantduring the run.

The method of this invention is carried out by controlling the torquetransmitted from the bobbin through the roving strand to the fiyer. Thistorque is usually much greater than the torque required to overcome thefriction in the flyers and connected elements, so that the gears illwhich are supposedly meant to drive the flyers are actually holding themback.

At constant winding tension, the torque transmitted from a single bobbinto the corresponding fiyer is proportional to the winding diameter, and,thus, the transmitted torque increases during the run, and reaches itsmaximum as the last layer of roving is being wound on the bobbin.

in actual practice, the magnitude of these torques and the flow ofenergy which they represent, has been calculated wherein the windingcycle was carried out on a conventional roving frame having theconventional type of cone drive for the bobbins. For example, aconventional roving frame with 108 spindles was winding 1.00 hankroving. The average density of the cotton on the full 10" x 5" bobbinwas 0.45 grams per cubic centimeter, which was found to correspond to anaverage winding tension of 750 grams. The machine was operated at aflyer speed of 926 revolutions per minute. The average stretch factorwas 1.04. Calculations showed that, when the last layer of roving on thebobbin had a diameter of 4.75 inches the torque transmitted from thebobbin to the flyer through the roving represented 6.6 horsepower. ()nlya relatively small percentage of this power was lost by friction. Mostof it was returned to the main shaft through the flyer drive. Further,calculations showed that out of the total power transmitted from thebobbins to the flyers, only 0.39 horsepower passed through the conedrive.

On the conventional roving frame, the variable speed cone pulley, i.e..the bottom cone, i geared to the shaft referred to as 124 in FIGURE 1.Shaft 124 i further connected through gears 123, 122, 121 to the innersleeve 114 in the differential compound carrying the sun gear 113. Thewinding r.p.m. is therefore directly proportional to the bottom coner.p.m.

in the present invention, the winding speed variator 125 replaces thecone drive of the conventional frame in pro viding the Winding r.p.m.The variator 125 receives its motion from the auxiliary drive shaft 139and delivers it to shaft 124, from which it is further transmitted tothe inner sleeve 114 of the differential compound. Auxiliary drive shaft139 is driven at a constant r.p.m. in fixed ratio to the constant r.p.m.of the front bottom drafting roll on shaft 4%. As already explained, thewinding tension will remain constant if the winding speed variator 125is regulated so that the winding power (Ev) remains constant.

The power transmitted by any shaft is proportional to the torquemultiplied by the r.p.m. Since, in the present case, constant windingtension and constant winding power go together, it follows that thewinding tension will be constant if the torque in the input shaft 132 ofthe winding speed variator 125 is constant. The problem of maintaining aconstant winding tension in the roving is thereby reduced to the problemof maintaining a constant torque in input shaft 132 of winding speedvariator 125.

To this end, the torque balancing device is provided and is embodied ina differential gear assembly, broadly indicated at 131, which also actsas a torque sensing and torque transmitting device. The torque balancingdevice 131 is interposed between auxiliary drive shaft 131 and the inputshaft 132 of winding speed variator 12.5. The torque balancer 131comprises a housing 133 journaled on the proximal ends of shafts 13-0,132, and being yieldably restrained from rotation by an externallyapplied control torque.

The combined torques in shafts 13%), 132 are transferred to housing 133as will be later described. Since the torques in the last-mentioned twoshafts 13-h, 132 are exactly equal and act upon housing 133 in the samedirection, an external control torque, equal to twice the torquetransmitted through the torque balancer 131 from shaft to shaft 132,must be applied to housing 133 to prevent its rotation.

The value of the external control torque (Q required to obtain a givenwinding tension (W) may be calculated from Equation II. Whenever thetorques acting internally upon housing 133 get out of balance with theexternal control torque, housing 133 will turn one way or the other.Through gears 145, 144, carried by housing 133 and a speed regulator orcontrol shaft 143, respectively, this movement of housing 133 istransmitted to the regulator shaft 143 of winding speed variator 125thereby changing the speed ratio of the variator 125 in such a mannerthat the various torques acting upon housing 133 get back into balance.It will be understood that a higher r.p.m. of output shaft 124 ofWinding speed variator 125 increases the torques acting internally onhousing 133, while a lower r.p.m. of shaft 124 has the opposite effect.The torque control is accurate in principle. The only inaccuracies arecaused by friction and similar mechanical imperfections.

The winding speed variator 125 may be a variable speed drive of anydesired or conventional construction as long as the r.p.m. of the outputshaft 124 may be infinitely varied relative to the r.p.m. of the inputshaft 132 through adjustment of an element thereof. In this instance,the winding speed variator 125 is shown as being of a wellknown typeincluding expansible cone pulleys 135, 136 mounted on the respectiveinput and output shafts 132, 124.

An endless belt 137 is entrained about pulleys 135, 136, and thedisplacement between the cones of respective pulleys 135, 136 is variedby means of a pair of levers 140 (FIGURE 2), corresponding ends of whichare pivotally connected to respective collars 142 penetrated byoppositely threaded portions of control shaft 143. As is well known,adjustment of control shaft 143 in one direction imparts movement tolevers 140 to move the cones of one of the pulleys 135, 136 toward eachother while moving the cones of the other of the pulleys away from eachother, and the pulley cones move in the opposite direction withadjustment of shaft 14-3 in the opposite direction.

In this instance, control shaft 143 has a gear 144 fixed thereon whichmeshes with a gear 145 suitably secured to or formed integral withhousing 133 of the torque sensing device 131. As heretofore stated,housing 133 contains differential gearing which is embodied in a pair ofrelatively large differential bevel gears or sun gears 148, 149 (FIGURE2) fixed on proximal, axially, alined ends of shafts 130, 132. A stubshaft 147 is journaled in housing 133 and has a planetary bevel gear 150fixedly mounted thereon which meshes with the two large differentialgears 148, 149.

Auxiliary drive shaft 130 is driven at a constant speed through directconnections with main drive shaft 10. The r.p.m. of shaft 130 maycorrespond to the fastest or starting r.p.m. of the conventional bottomcone which is omitted in this instance and replaced by shaft 130.

Housing 133 may be yieldably restrained from rotation by means of torquecontrolling weight B depending from pliable element or cable 151 whichis wound about drum 152. Drum 152 may be in axial relationship to shafts134), 132. The end of the pliable element 151 remote from weight B issuitably attached to the drum 152.

The mass of the weight B should be chosen such that it will exert atorque on the housing 133 at the torque balancer, equal to twice thetorque to be transmitted through the torque balance from shaft 130 toshaft 132. Further, the position of the variator speed control shaft 143and the gear 144 thereon should be such that the r.p.m. of output shaft124 will cause rotation of the bobbins 31 at exactly the correct r.p.m.to establish the desired winding tension in the strand of roving Rbetween the presserfoot 28 of each ilyer 22 and the respective bobbin 31as the first layer of roving is deposited thereon, at which stage theweight member B will occupy its lowermost position spaced substantiallyfrom the drum 152 of torque balancer 131.

Auxiliary drive shaft 1311 is gear-driven from top cone shaft 50.Referring to FIGURE 2, it is apparent that input shaft 132 of thewinding speed variator will rotate in the opposite direction from shaft135. Therefore, in this particular embodiment, auxiliary drive shaft 136is driven in the opposite direction from that at which the usual bottomcone is driven. However, it is to be understood that other elements ofthe roving frame may be so arranged that shafts 130, 132 may rotate indirections opposite from those indicated herein.

In this instance, top cone shaft 55 has a gear 153 fixed thereon andengaging a gear 154 integral with or rotatable in fixed relation to asprocket wheel 155. Sprocket wheel 155 is engaged by an endless sprocketchain 156. Chain 156 also engages a sprocket wheel 157 mounted onauxiliary drive shaft 130. Sprocket wheel 157 may be fixed on auxiliarydrive shaft 130, but it is preferably connected with shaft by means of asuitable overriding clutch mechanism as best shown in FIGURE 10. Thisoverriding clutch mechanism may be provided in order to permit shaft 130to be rotated independently of sprocket wheel 157, as will be more fullydescribed hereinafter.

To illustrate the principles of this invention, the derivation ofEquations I and II will now be shown.

In general, the power (E) in HP. units (1 H.P.=746 watts) transmitted bya shaft rotating at a rate of n r.p.m. carrying a torque of Q graminches is The torque acting between a bobbin and a flyer as a result ofthe winding tension in the roving is W D/ 2 gram inches, where W is thewinding tension in grams, and D' is the momentary value of the effectivewinding diameter of the bobbin in inches. The winding power (Ev) is thepower consumed when this torque acts against the winding r.p.m., whichmay be referred to by the symbol V. The winding r.p.m. is the differencebetween the bobbin r.p.m. and the flyer r.p.m.

In analogy with Equation V, the winding power (Ev) in a roving framewith m spindles is Since the yardage of roving taken up by the bobbinmust be equal to the yardage delivered by the front drafting rollsmultiplied by the stretch factor f, we have where is the r.p.m. of thefront bottom drafting roll having a diameter of d inches.

Substitution of Equation VII in VI gives As heretofore stated, EquationI shows the total wind ing power (Ev) in HP. units in a roving framewith "m spindles, operating under a winding tension of W grams in eachstrand of roving, Where the front bottom drafting roll has a diameter ofd inches and rotates at a rate 0; r r.p.m., and where the stretch factorhas a value 0 C M It is of interest to note that Equation I could havebeen developed without reference to any particular Winding mechanism. 1rd r is the rate in inches per minute at which the roving is deliveredfrom the front rolls for any one winding spindle. If this is multipliedby f and by m, it becomes the rate in inches per minute at which theroving is taken up by all the spindles combined. W 1r d r f m istherefore the total winding power in gram inches per minute for thewhole machine. The numerical factor 1.748 10"* includes 1r andtransforms the winding power (Ev) into horsepower units.

If we assume that the input shaft 132 to the winding speed variator 125is rotating at a rate of n r.p.m. carrying a torque of Q gram inches,then the power in HP. units (E) transmitted by that shaft is given byEquation V.

1.3 Since the external control torque Q acting upon the torque balancehousing 133 must be twice the torque transmitted by shaft 132, we haveIntroducing Equation VIII in V, we get another expression for the totalwinding power in the machine; i.e.,

By F we shall understand the ratio between the r.p.m. (r) of the frontbottom drafting roll shaft 4% and the r.p.m. (n) of shaft 132; i.e.,

r=F n From Equations I, IX, X, follows by substitution Qn F W f (II) Thesignificance of Equation II and the meaning of the symbols has alreadybeen discussed.

When the automatic tension regulator of the present invention is used,Equation II provides a simple method for calculating the control torque(Q which must be applied externally to housing 133 of torque balance 131to produce the desired value of the winding tension (W). Since theserelationships are exact, there is no other uncertainty involved thanthat resulting from the frictions between intervening mechanicalelements of the machine. This uncertainty is usually negligible and neednot be considered. Accordingly, the torque balance 131 and weight B,producing the control torque (Q in the embodiment set forth herein,sense a torque proportional to the torque between the relativelyrotating bobbins and flyers to thus give a measure of the torquetherebetween, so that the automatic tension regulator of the presentinvention is also a measuring instrument, whereby the winding tensioncan be accurately determined. Furthermore, the automatic regulatorlimits the winding tension effectively to the chosen value, thuspreventing excessive winding tension which could damage the machine. Theneed for such a protection has become considerable due to the highwinding tensions that recently have come into use.

The following is an example of how the tension regulato? of the presentinvention may be used with an otherwise conventional roving frame.Referring to FIGURE 1 we may assume that the designated gear andsprocket elements have the following number of teeth:

(Element) (Number of teeth) 48 66T 49 921 153 301 154 30T 155 ZOT 1575ST We may further assume that the front bottom drafting roll has adiameter of d=1.125 inches, and that, driven by gear 49, this rollrotates at a rate of r=234 r.p.m. The frame has m=108 spindles. Making arelatively dense package of 1.00 hank roving, the average windingtension is W=750 grams. The stretch factor has an average value off=l.04.

The ratio (F) between the r.p.m. of the front bottom drafting roll (r)and the r.p.m. (n) of input shaft 132 is then From the Equation 1, itfollows that the total winding power (Ev) is From Equation II, itfollows that the required control 1 a torque (Q which must be appliedexternally to housing 133, is

186600 gram inches.

These calculations show that in order to obtain the desired windingtension of W :750 grams, the control torque must be Q =186600 graminches. The power transmitted by the winding speed variator is 0.39 HP.

The control torque (Q must act in the same direction as top cone shaft50 rotates. Assuming drum 152 to have a diameter of 2.49 inches, weightB must be kilograms. In fact, with the design details as given above,weight 13 must always be 200 times as heavy as the desired windingtension in the individual strand of roving (w). By varying the weight B,any desired winding tension can conveniently and accurately be obtained.The winding tension may be adjusted to suit the individual case, and itsactual value will always be exactly known.

Since the diameter of drum 152 influences the torque (Q caused by weightB, it follows that the winding tension can be made to vary during therun according to a predetermined program by giving drum 1% anoncylindrical contour. To compensate for the torques resulting fromfrictions, an additional non-cylindrical drum, with an additional stringand an additional Weight, may be axially attached to drum 1152.

Drive for auxiliary drive shaft The overriding clutch mechanism shown inFIGURE 10 is of a well-known type and comprises a polygonally ortriangularly shaped internal block which is fixed on shaft 130 and whosefiat peripheral surfaces are each engaged by a ball or roller 161normally biased toward the desired direction of rotation of sprocketwheel 157, as by a tension spring 162. Each ball 161 is adapted toengage the inner surface of a circular cavity 163 formed in sprocketwheel 157. Thus, counterclockwise rotation of sprocket wheel 157 inFIGURE 10 imparts corresponding rotation to auxiliary drive shaft 130.On the other hand, shaft 130 may be driven while sprocket wheel 157remains stationary in order to perform a resetting operation to be laterdescribed.

It will be noted that shaft 130 also has a sprocket wheel 165 mountedthereon by means of a suitable overriding clutch mechanism (FIGURE 8)which may be identical to the overriding clutch mechanism (FIGURE 10)shown in association with the sprocket wheel 157. Since the clutches ofFIGURES 8 and 10 may be identical, the parts of the clutch shown inFIGURE 8 shall bear the same reference characters as like parts inFIGURE 10 with the prime notation added. Accordingly, a further detaileddescription of the overriding clutch mechanism shown in FIGURE 8 isdeemed unnecessary.

Sprocket wheel 165 is engaged by an endless sprocket chain 167 whichalso engages a sprocket wheel 1'70 (FIGURE 1) mounted on the shaft of aslow speed auxiliary electric motor 172. Motor 172 serves to reset thetension regulator before the start of each winding cycle, as will belater described. Motor 172 drives auxiliary drive shaft 130independently of sprocket wheel 157 and imparts relatively slow rotationto the bobbins 31, in the normal direction of rotation during theresetting operation, without imparting motion to many other elements ofthe machine.

Braking device Since the weight B is relatively heavy, locking means areprovided to restrain housing 133 from movement under influence of weightB when the machine is not operating. Any suitable restraining means maybe provided for this purpose and, in the present embodiment of theinvention, it will be observed in FIGURES 2 and 3 that gear 145 isspaced from the body of housing 133 sufficiently to provide a brake drum175, of a braking or locking device 179, on housing 133.

Braking drum 175 is adapted to be engaged by a brake band or shoe 176carried by a brake lever 177. Brake lever 177 is pivoted, as at 181),and is normally biased toward brake drum 75, as by a spring 181. Asolenoid plunger 182, connected to the other end of lever 177, issurrounded by a solenoid coil 1% to which electrical conductors 184, 185are connected. Conductor 185 leads to one side of a normally closedswitch g of a time-delay-relay 138, from the other side of which aconductor 139 extends.

Relay 188 may be of any desired or conventional construction, such as isdisclosed in United States Patent No. 2,751,621, just so long as relay188 is capable of delaying energization of solenoid 183 for apredetermined interval following energization of the main drive motor12, so that main drive motor 12 may reach full speed before the brakeshoe 176 is moved away from brake 175.

In this instance, time-delay-relay 188 comprises a housing a having anadjustable air escapement valve 12 thereon and a diaphragm c therein.Diaphragm c is engaged by a solenoid plunger e having switch bar gthereon and being encircled by a solenoid coil p. Switch bar g normallyestablishes contact between conductors 185, 189. Conductors r, s areconnected to opposite ends of coil p, conductor 1' being connected to alead wire or conductor L-1, and conductor s extending to a normally opendouble-pole, push-button start switch 202. Corresponding ends ofconductors L-1, L2 are connected to a suitable source of electricalenergy embodied in a plug P.

Conductor 184 is connected to a conductor 184a by means of a normallyclosed relay switch 1114b. Conductors 186, 187 extend from therespective conductors 184a, L-1 to opposite sides of the main driveelectrical motor 12. Conductors 184a, L-2 lead to a relay 192 having apair of switches 193, 194 therein which are normally open to the maindrive circuit, but which are closed upon energization of a relay coil1%.

One end of relay coil 1% is connected to lead conductor L-1 and theother end of coil 1% is connected, by a conductor t, to a normallyclosed push-button stop switch 1%. The side of switch 197 opposite fromconductor t has a conductor 2% leading therefrom to one side of thenormally open side of switch 193 in relay 192, and the other side ofswitch 193 has lead conductor L2 connected thereto.

Conductor L-2 is also connected to switch 1%. Conductor L-2 has aconductor 261 leading therefrom to the side of start switch 292 oppositeconductor s. When switch 2412 is depressed, it establishes contactbetween conductors 201 and s. At the same time, switch 202 establishescontact between a conductor 20 2- and a conductor 2%. Conductor 2414leads to conductor 2111 and conductor 2115 leads to coil 1% of relay 192through conductor t.

It is apparent that when start switch 262 is depressed, it energizesrelay coil 196 to move switches 193, 1% downwardly and also energizescoil p of time-delay-relay 188, thus breaking the normally closedcircuit to the brake solenoid 183 practically simultaneously with theclosing of the circuit thereto so that the brake actually remainslocked; that is, brake shoe 176 remains against the drum 175 as the maindrive electric motor 12 is energized.

Since start switch 2112 is released shortly after it is depressed by theoperator, stop switch 197 maintains the flow of current through the coil1% of relay 122, but coil p of time-delay-relay 188 is de-energized.Accordingly, after a predetermined interval established by adjustment ofvalve b, the switch bar g returns to closed position to energize coil183 and move brake shoe 176 out of engagement with brake band 175, thusproviding an interval of time suflicient for the motor 12 to reach fullspeed before brake shoe 176 is released and moved out of 15 engagementwith brake band 175. Otherwise, the torque developed by the auxiliarydrive shaft 131 would be insufiicient to maintain the weight in raisedposition if it happened to be in raised position at the time the rovingmachine had been previously stopped.

It is apparent that, at the end of the run, or at any time duringoperation of the machine, stop switch 197 may be depressed and, sinceswitch 202 is then out of contact with the proximal ends of conductors294, 205, this will break the circuit to the coil 196 of relay 192, thusreleasing switches 1%, 194 and breaking the circuit to electric motor 12and solenoid 183 to stop the machine and simultaneously cause brake shoe176 to move against brake band 175.

From the foregoing, it is apparent that brake band 176 engages drum 175and prevents unintentional rotation of housing 133 of the torque sensingdevice 131 Whenever main drive electrical motor 12 is de-energized andthe roving frame is not operating. it is apparent that motor 12 may becontrolled by a circuit independent of those remaining elements of themain circuit of FIGURE 3 heretofore described, and switch 197 may thenbe disposed in the path of the usual shipper so as to break the circuitto solenoid coil 183 whenever the roving frame is stopped, even thoughthe main drive motor 12 may continue to rotate. Since the latter is theequivalent of the circuit of FIGURE 3 thus far described, anillustration thereof is deemed unnecessary.

Resetting means for tension regulator At the end of a run, the variousoperating elements of the automatic tension regulator must be reset;that is, control shaft 143 for speed variators 125, 245 must be rotatedto return the cones of pulleys 135, 136 to starting position, and weightB must be lowered to starting position. As heretofore stated, thisresetting operation is effected by auxiliary motor 172.

Referring again to FIGURE 3, it will be observed that auxiliary motor172 has conductors 210, 211 connected to opposite sides thereof.Conductor 216 extends from auxiliary motor 172 to one end of the coil uof relay 1841;. The other end of the coil u has a conductor 212 leadingtherefrom to conductor 184.

Conductor 211 extends from auxiliary motor 172 to one side of a normallyopen relay switch 213, the other side of which has a conductor 214leading therefrom to one side of a normally open manual push-buttonreset switch 215. The other side of reset switch 215 has a conductor 216leading therefrom to the switch 193 associated with relay 192. Switch193 establishes contact between conductor 216 and a conductor 217 whenrelay coil 196 is deenergized. The other end of conductor 217 leads to amedial portion of conductor 210.

One end of the coil y of relay 213 is connected to conductor 214 and itsother end has a conductor 220 leading therefrom to one side of anormally closed reset stop switch 221. The other side of switch 221 hasa conductor 222 leading therefrom to conductor L2. The switch 221 may bepositioned at any desired location so as to break the circuit toauxiliary motor 172 when the resetting operation has been completed;that is, when the Weight B has been returned to its lowermost position.In this instance, switch 221 is shown suitably supported so as to beengaged by weight B when it reaches lowermost position at the end of theresetting operation.

As heretofore stated, motor 172 serves to reset torque sensing device131 following each winding cycle and prior to the next succeeding cycle.It follows, therefore, that main drive motor 12 remains de-energizedduring the energization of electric motor 172 or, at least, during theresetting operation.

Since the overriding clutch (FIGURE l0) is provided in sprocket wheel157, and sprocket chain 156 is not driven during the resettingoperation, electric motor 172 drives shaft in the same direction inwhich it is driven during normal operation of the roving machine, but ata considerably slow speed. This shaft must be driven during theresetting operation in order to rotate the pulleys 135, 136 of variablespeed drive 125. Of course, shaft 133 also drives the pulleys of theauxiliary or second variable speed drive 245 in a like manner. Thus,this avoids placing the threads on the opposed ends of the control shaft14-3 under excessive pressure.

As will be explained more in detail hereinafter, brake shoe 176 isreleased relative to drum 175; that is, brake shoe 176 is moved awayfrom drum 175, during the resetting operation so that housing 133 oftorque sensing device 131 may be moved solely by the weight of weight 8.However, since the weight B is relatively heavy, a suitable torqueabsorbing means should preferably be employed in order to preventhousing 133 from placing gear 14 d and control shaft 143 under excessivetorque. In other words, the control shaft 143 should not be relied uponas the sole means to absorb the torque produced in the housing 133 bythe weight B in the absence of suiiicient torque between shafts 131i,132 to support weight B. Otherwise, the control shaft 143 and thethreaded members 142 of variable speed drive 245 would have to beexcessively large.

Accordingly, I have provided a simple torque absorbing apparatus whichis effective only during the resetting operation. Said torque absorbingapparatus is broadly designated at 233 and comprises a pair ofinterconnected coaxial gears 231, 232. Gear 231 engages gear 145 and isfixed on a shaft 233 on which gear 232 is also secured. Shaft 233 may bejournaled for free rotation in any desired manner, such as by hearingmeans carried by the frame of variable speed drive 125. Gear 232 mesheswith a gear 234- which is preferably of substantially the same diameteras gear 145 and which is mounted on shaft 132 by means of a suitableoverriding clutch mechanism similar to that shown in FIGURES 8 and 10,and as is shown in FIGURE 11. Since the clutch mechanism associated withgear 23-:- and shaft 132 is substantially the same as the clutchmechanism of FIGURE 10, except being effective in the oppositedirection, those elements of FIGURE 11 which correspond to like elementsof FIGURE 10 shall bear the same reference characters with thedouble-prime notation thereafter to avoid repetitive description.

it is apparent that, when a balanced torque exists between shafts 133,132 and housing 133, shaft 132 is the driver in FIGURE 11 and is, thus,free to rotate independently of the gear 233. On the other hand, duringthe resetting operation, shaft 132 rotates relatively slowly and thereis no appreciable torque between shafts 130, 132 so that housing 133 isfree to rotate in the opposite direction from auxiliary drive shaft 130and in the same direction as shaft 132. However, since shaft 132 is thenrotating at a substantially slower speed than that at which the gear234- would rotate; if it were free to do so, gear 233 would become thedriver relative to shaft 132 and,

- thus, housing 133 cannot rotate, during the resetting operation, at aspeed any greater than that of the shaft 132, thus relieving gear 144-and control shaft 143 from excessive torque during the resettingoperation.

Operation of bobbin drive it is to be assumed that the resettingoperation has been completed so that weight B occupie lowermost positionand variator 125 is so arranged that, upon starting the machine, thehighest desired rate of output speed will be imparted to the shaft 124in the lower left-hand portion of FIGURES l and 2, since the outputspeed of variator 125 gradually decreases as the bobbin diameter orpackage diameter increases. In other words, the flyer speed is constantthroughout the wind and the bobbin speed gradually diminishes as thediameter of the bobbin increases.

The roving R is threaded through flyers 22, wrapped around presserfeet28 thereof a few times, and then a few turns are wrapped around thebobbins by the operator. Thereupon, start switch 202 is depressed by theoperator to establish contact between respective conductors 201, t and264, 205. As heretofore stated, this energizes the coil 2 oftime-delay-relay 188 and the coil 196 of relay 192 to energize maindrive electric motor 12 and also insures that coil 183 associated withthe braking device 179 (FIGURE 3) remains de-energized until electricmotor 12 has reached full speed. Thereupon, switch bar g establishescontact between conductors 185, 189 to release said braking device 179.It is to be understood that relay 18 5b occupies closed position at thistime primarily because relay 213 occupies open position. Even thoughreset switch 215 might accidentally be pressed while electric motor 12is energized, switch bar 193 will then be spaced from the proximal endsof conductors 216, 217 so that electric motor 172 and the coil of relay1841; will remain de-energized.

As already mentioned, weight B applies a predetermined control torque (Qto housing 133 of the torque balancer 131, equal to twice the torquetransmitted by either shaft 130 or shaft 132.

If the regulator were inactive, the winding tension would increasesteeply with increasing bobbin diameter. But the higher winding tensioncauses an increased torque in shafts 130, 132 whereby housing 133carrying drum 152 is made to turn in the positive direction; i.e.,clockwise when seen from the right, raising the weight B. Through gears145, 144 the rotation of housing 133 is transmitted to the commoncontrol shaft 143 of the two variators 125,

245, causing their output shafts, respectively 124 and 246, to slowdown. The reduced r.p.m. of output shaft 124 from variator causes aproportional reduction in the winding r.p.m., whereby the excessivewinding tension is relieved, and the regulator is again returned toequilibrrum.

By keeping friction losses to a minimum, the regulator can be made verysensitive. Since it acts continuously, the movements are very slow andgradual.

As the bobbin diameter increases the r.p.m. of output shafts 124, 246from variators 125, 245 respectively continues to decrease, and weight Bcontinues to rise. The total traverse of weight B from the beginning tothe end of the run obviously depends on various design details, such asthe number of revolutions that shaft 143 must make to cover the requiredspeed range, the relativ number of teeth in gears 145, 144, and thediameter of drum 152.

At the end of the winding cycle, the circuit to electric motor 12 may bebroken automatically by conventional means well known in the art, butnot shown in the present drawings, or the manual stop switch 197 may bedepressed, to also stop further rotation of electric motor 12. Referringto FIGURE 3, it is apparent that, when stop switch 197 is depressed, thecontact between conductors 200, t is interrupted, and the circuit tocoil 1% is broken, so that switches 193, 194 break the circuit betweenconductor L-2 and conductors 200, 184a.

At the end of each winding cycle, and immediately before electric motor12 is de-energized in the manner described, it is necessary to producesufficient slack in the roving between the drafting rolls and the flyersto facilitate lifting the flyers 22 off the respective spindles 21 andremoving or dofling the filled bobbins from the spindles and bolstersassociated with the usual bolster rail 35. In order to producesufficient slack between the drafting rolls and the flyers for thedoffing operation, the fiyers 22 and bobbins 31 should preferably berotated at the same speed for a relatively short period so that theroving is not taken up by the bobbin, but accumulated on top of theflyer.

Accordingly, shaft 124 preferably is split into two coaxial sections124a, 12411, and a suitable manually operable clutch 243 may beinterposed between and connected to the proximal ends of said sectionsof shaft 124. Thus, main drive shaft 11} then drives compound 49 and,since sleeve 114 thereof (FIGURE 7) is not driven at this time, thiseffectually interlocks the sleeves 114 and 115 relative to housing 11%so the bobbins are driven directly by the main shaft 10. Thus, bobbins31 and flyers 32 operate at the same speed. When sufficient slack hasbeen produced in the roving, the stop switch 197 (FIGURE 3) is depressedby the operator, and clutch mechanism 240 is released to again establisha fixed relationship between the two sections 124a, 1241) of shaft 124.

It is apparent that, since the flow of current between conductors 185,189 at switch g is also interrupted when stop switch 197 is depressed,spring 181 will also actuate the brake device 179; that is, spring 181will return brake shoe 176 into engagement with brake band 175 at thesame time that main drive electric motor 12 is tie-energized.

After the dofi'ing operation, empty bobbins, along with the flyers 22,are mounted on the spindles 21 and the resetting operation is effectedin the manner heretofore described. It will be noted in FIGURE 3 thatelectric motor 172 is energized for the resetting operation bydepressing the normally open manual reset switch 215. Thereupon, currentflows from lead wire L-2, through switch 221, conductor 220 and the coily of relay 213. It might be stated that, at the time reset switch 215 isdepressed, weight B is spaced substantially above switch 221 so thatswitch 221 then occupies closed position.

Current flows from the end of coil y remote from conductor 220, throughconductor 214, reset switch 215, conductor 2116, relay switch 193,conductors 217 and 210, the coil u of relay 184b, conductors 212, 184,through the solenoid 183, conductors 185, 189 and lead conductor L-1.This opens relay 18412 and closes relay 213.

Relay 1841) is provided so as to prevent current from flowing throughmain drive electric motor 12 during the resetting operation.

From the foregoing, it is apparent that when relay 213 is closed,current flows from the coil y of relay 213, through the switch portionof relay 213 and conductor 211 to electric motor 172. Current flows fromthe other side of electric motor 172 through conductor 210, through thecoil u of relay 184b, conductors 212, 184, solenoid 183 and thence tothe lead wire or conductor L-l in the manner heretofore described. It isthus seen that, although switch 215 may be released followingenergization of the coil relay 213, the coil of relay 213 remainsenergized and, therefore, electric motor 172 remains energized.

As heretofore stated, since the main drive electric motor 12 is thende-energized, shaft 130 is rotated solely by electric motor 172, and theoverriding clutch in the sprocket wheel 157 (FIGURES 2 and 8) permitsshaft 130 to rotate in its normal direction without irnparting rotationto sprocket whee-l 157. Therefore, the bobbins 31 are rotated relativelyslowly while the flyers 22 remain stationary.

Since solenoid 183 is also energized at the time of energization ofelectric motor 172, brake shoe 176 is moved away from brake band 175during the resetting operation so that the housing 133 of torque sensingdevice 131 is free to rotate by the weight of weight B, with theexception of the effect produced by the torque limiting device 239interposed between the shaft 132 and the housing 133.

Once the resetting operation has commenced, the operator need no longerbe concerned with it, since, upon completion of the resetting operation,the weight B will open switch 221 to break the circuit to the coil ofrelay 213 and, thus, to the electric motor 172 and the coil of relay184k. After the resetting operation has been 2i) completed, the strandsof roving extending from the drafting rolls D are then threaded throughthe flyers 22 and then wrapped around the bobbins 31 in the mannerheretofore described to thus complete a cycle in the operation of thetorque sensing device 131 and the associated winding tension regulator.

Traverse motion drive The bottom cone shaft on a conventional rovingframe provides the winding r.p.m. (V), and it also provides the verticaltraverse motion of the bobbin carriage. By the lay speed (L) we mean thelinear traversing velocity of the bobbin carriage, expressed in inchesper minute.

Since the coils per inch (U) are equal to the ratio of the windingr.p.m. (V) to the lay speed (L), we have U: V/L (Xi) The r.p.m. of thebottom cone diminishes during the run, but since both the winding r.p.m.(V) and the lay speed (L) are derived from the bottom cone of priorroving frames, the ratio between them; i.e., the coils per inch (U),remains constant.

In the method of the present invention, it is no longer practical todraw both the winding rpm. (V) and the lay speed (L) from the samevariator. To obtain effective regulation of the winding tension, thewinding power (Ev) must be isolated in a separate variator.

In addition to the winding speed variator 125, I have, therefore,provided the separate lay speed variator 24 5. For descriptive purposes,assume that the two variators are of identical design. Further assumethat variators 125, 245 are actuated together by the rotation of thetorque balance housing 133, transmitted through gears 145, 144 tovariator control shaft 143.

If the two variators are of identical design and they are actuatedtogether in identical manners, the ratio of the winding r.p.m. (V) tothe lay speed (L), i.e., the coils per inch (U), may still remainconstant during the run, if this should be desirable. It has long beenknown, however, that the independent regulation of the winding rpm. andthe lay speed, for example, by means of two sets of cone pulleys, offersimportant advantages, but also that it introduces additionaldifiiculties. It is therefore not generally done.

On the other hand, the flexibility of the automatic tension controlaccording to the present invention makes it possible to obtain the fulladvantages of a non-uniform lay spacing adapted to fit the individualcase, without any related difficulties. Since this is a major advantageof the present method, it will now be explained in detail why this isso.

A perfect roving bobbin was defined above as a bobbin where every yardof roving has exactly the same stretch factor. It was explained thatwhen such a bobbin is analyzed, the density of the fibrous material isfound to decrease along any radius from the core to the outside of thebobbin. The density gradient is non-uniform and follows a definitemathematical law, which, unfortunately, differs somewhat with fiberproperties, density levels, etc., and in no case has been accuratelydetermined.

For the present purpose, it is sufficient to be aware of the fact thatthe density distribution in a perfect bob-- bin is given by nature. Itis something which must be accepted as it is, because it cannot bechanged. An old, and as yet largely unsolved, problem is to give theconventional cone pulleys such a curvature that they will reproduce thedensity distribution of a perfect bobbin.

It is necessary to distinguish clearly between the coils per inchmeasured in the axial direction of the bobbin, and the layers per inchmeasured along a radius. The weight of a small unit volume of thefibrous material anywhere in the bobbin is under otherwise equalconditions proportional to the product of the coils per inch and thelayers per inch. Both quantities have therefore an equal influence uponthe density at any given location in the bobbin. But, a given densitydistribution can be produced by many different combinations in thespacing of the coils and the layers. This applies also to the densitydistribution in a perfect bobbin. It is the density distribution itselfthat matters. It does not matter how it is produced.

A conventional roving frame normally operates with constant coils perinch. The radial density gradient is achieved by gradually allowing eachnew layer of roving more space in the radial direction as the runproceeds. The curvature of the cones has been designed for that purpose.

Suppose that such a roving frame actually is producing a perfect bobbin,but then a change is made so that the coils per inch now are decreasingduring the run. The layers will then be spaced as they were before, butdue to the progressively fewer coils per inch the density will diminishin the radial direction more rapidly than it should. The winding tensionwill fall off towards the end of the run, the roving in the outer layersof the bobbin will be heavier than it should be, and an assortment ofoperating difficulties will be encountered.

The variations in the coils per inch are therefore interrelated to thevariations in the layers per inch through the required density gradient.Due to this inherent relationship, any attempt to control these twoquantities separately by the usual inflexible means, such as two pairsof cone pulleys, is likely to prove impractical.

The present invention eliminates these limitations entirely. The coilsper inch may be varied during the run according to any program. Theautomatic tension regulator will space the layers accordingly, so that aperfeet bobbin with the correct density distribution will be obtained inany case.

To obtain the conical shape of the end surfaces of the bobbin, thelength of the traverse stroke is usually shorterred by a constantincrement for each new layer of roving. On the other hand, on aconventional frame operating with constant coils per inch, the diameterincrements per layer are gradually increasing during the run. Theconstant increments in the vertical direction combined with theincreasing increments in the horizontal direction tend to give the endsurfaces of the bobbin a more or less concave contour. This isdisadvantageous, both because it reduces the volume of the bobbin andbecause it increases the tendency of the roving to overrun or slough offat the two ends of the bobbin towards the end of the run. The overrunsare a constant problem in roving frame operations.

From what has been stated above regarding the interrelation of the coilsper inch and the layers per inch through the radial density gradient ofthe bobbin, it will be understood that, through a progressive decreasein the coils per inch during the run it is possible to diminish, or evenreverse, the negative progression in the layers per inch; i.e., byplacing the coils progressively farther apart during the run it ispossible to make the layers become progressively closer together. Theconical end surfaces of such a bobbin will have a convex, rather than aconcave, contour. By suitable adjustment of the progression in the coilsper inch, it is thus possible in principle to give the end surfaces ofthe bobbin almost any contour.

This is fortunate. While a convex contour of the end surfaces of thebobbin is generally desirable, the best contour curve can, as a rule,only be found by the trial method. The curve will differ with the fibermaterial, the hank number, the density level, the mechanical conditionof the machine, and with other variables. There are no definiteapplicable rules for determining the desired curvature.

From the foregoing, it may be understood that, in the method of thepresent invention, it is usually desirable to control the coils per inchand the layers per inch simultaneously in an interconnected manner fromthe 22 movement of an element equivalent to the torque balance housing133, but the two regulations do not necessarily need to follow the samepattern. Consequently, the variators 125, 245 need not be of the samedesign.

In FIGURES l and 2, the variators 125, 245 are shown to be of the samedesign, and it is indicated that they are controlled in identicalmanners through the common control shaft 143 which derives its rotationfrom torque balancer housing 133.

As far as the traverse motion is concerned, lay speed variator 245 takesthe place of the conventional cone drive. It obtains its input powerfrom auxiliary drive shaft which rotates at the same r.p.m., but in theopposite direction as compared to shaft 132, which serves as input shaftfor winding speed variator 125. Corresponding parts of the two variatorstherefore rotate in opposite directions. Output shaft 246 of lay speedvariator 245 is connected, by sprocket wheels 2'47, 248 and chain 251,to the same train of gears, 56,. 57, 58, 62, 63*, etc., whichconventionally is connected to the bottom cone shaft as previouslydescribed.

As indicated in FIGURE 12, variators 125, 245 may be controlled togetherbut in an adjustable interrelation to each other. As shown in FIGURE 12,this may be achieved by dividing control shaft 143 in two parts orsections, 143a, 14%, each serving a separate variator. interposedbetween sections 143a, 1439b is a normal change gear assembly,comprising gears 260, 262, 263, 261. By changing one or more of thesegears, the gear ratio between shafts 143a, 143b can be given any desiredvalue. It should be understood, however, that instead of the illdicatedchange gear assembly, other means with other characteristics may be usedfor the interconnection of shafts 143a, 1431;.

Conclusion The method of tension control of the present inventiondiffers radically from those of any known prior art, par ticularlybecause there is an automatic adjustment to many uncontrollablevariables which otherwise would influence the final result.

Although a particular type of torque sensing and controlling mechanismand a particular type of variable speed transmission have beendisclosed, it is apparent that many different types of such devices mayreadily be adapted to existing or new roving frames for the purpose ofcontrolling what I have referred to as the winding power, withoutdeparting from the spirit of the invention.

Although the method of the present invention, and the functions of thetension regulating system, have as their immediate object the control ofthe winding tension, the controlled winding tension is not in itselfparticularly important, because it seems that the elongation of theroving between the presserfoot and the bobbin is limited to about 3 to 4percent, and this elongation appears to have low sensitivity to changesin winding tension particuiarly when the tension already is high.

The elongation of greatest significance seems to occur somewhere betweenthe nip of the front drafting rolls and the presserfoot, probably mostlybetween the nip of the rolls and the top of the flyer. This elongation,which may be as low as 2% and as high as 10% with the frame stillrunning, depends upon a complex interaction of several factors,including the nature of the fiber material, the amount of real or falsetwist in the roving, the amount of tension, etc. The operatorconventionally tries to control the elongation at this stage bycontrolling the tension as he sees it and feels it, but this method ofcontrol is highly unsatisfactory. Various attempts have been made tocontrol the roving frame automatically by means actuated from thetension in the roving between the front roll nip and the top of theflyer, but so far without practical success.

The tension in the roving at the top of the fiyer is proportional to thewinding tension. Since the present invention permits an accurate controlof the winding tension, it also accurately controls the tension at thetop of the flyers. The elongation of the roving at that point is therebykept under control.

Thus, the invention eliminates weight variations in the roving whichhave occurred heretofore due to faulty cone curvature and othermechanical shortcomings, and it also makes it possible to dealeffectively with weight variations due to the human factor.

In most mills, there is a tendency to start each run with too muchtension in the roving. The first few layers of roving on the bobbin maythereby be stretched to percent more than the average of subsequentlayers, and the difference may still be measurable after several hundredyards of roving have been put on the bobbin. Due to the recent trend ofspinning all yarn from a single strand of roving, the resultingvariations in the weight of the roving are fully reflected in the weightof the yarn.

There are many reasons why the start of each run with excessive windingtension is, to some extent, unavoidable. Unless the first layer ofroving deposited on the smooth surface of the wooden bobbin is woundunder adequate tension, the fiber material will not remain stationary,but will gradually creep over the top of the wooden bobbin, making itnecessary to put the material into waste.

By means of adjusting screw b of time-delayrelay, or by suitablemodification of the electrical control system for the automatic tensionregulator, the first layer of roving may be wound against the barewooden bobbin under relative high tension. Action of the automatictension regulator could thus be delayed until the traverse motion hasbeen reversed the first time. The roving deposited directly on the bareWooden bob-bin could thereby be overstretched, but since this is arelative small length and it generally is not used anyway, it does notmatter. The rest of the roving on the bobbin would then have the correctweight.

Recently, there has been a trend to achieve higher bobbin densities bywrapping the roving one or two additional times around the presserfinger 27 and simultaneously make appropriate changes in the lay andtension gears. Research on these questions has brought out the factthat, for any given hank roving, there is a definite relationshipbetween the average bobbin density and the Winding tension. The tensionincreases very steeply when the average density of a 10" x 5 bobbinexceeds 0.450.48 grams per cubic centimeter whereby the frame may thusbecome mechanically overloaded.

Density determinations, being somewhat cumbersome, are not customarilymade. The operator therefore does not usually know anything about theload carried by the various parts of the frame. In some cases he may beovercautious. In other cases, he may unknowingly go far beyond thesafety limits. My invention eliminates all uncertainty in this respect,because the winding tension is always accurately known.

In the drawings and specification, there have been set forth preferredembodiments of the invention and, although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being defined in theclaims.

I claim:

1. A method of controlling the winding speed in a roving frame havingrotating flyers for traversing roving onto rotating bobbins whichcomprises sensing at least a measure of the torque between the flyersand the bobbins, and varying the relative speed between the flyers andthe bobbins in response to variations in the torque so sensed.

2. A method of maintaining a constant predetermined winding tension in astrand of roving as it passes from drafting rolls through a rotatingflyer and as it is wound on a corresponding rotating bobbin, whichcomprises continuously detecting relative changes in the torque betweenthe flyer and the bobbin during continuous rotation of the fiyer and thebobbin and simultaneously regulating the 2 irelative speed between thebobbin and the flyer in response to the relative changes in the torquebetween the flyer and the bobbin.

3. A method of controlling the Winding speed in a roving frame havingrotating flyers for trasversing roving onto relatively rotating bobbinswhich comprises sensing at least a measure of the average torque betweenall the flyers and all the bobbins on the roving frame, and varying therelative speed between the flyers and the bobbins during rotation of theflyers and the bobbins in response to variation in the torque so sensed.

4. In a roving frame having rotating flyers driven at a constant speedfor directing roving from drafting rolls to respective relativelyrotating bobbins; the method of controlling the winding speed betweenthe flyers and the bobbins which comprises sensing the torque betweenthe flyers and the bobbins, applying a predetermined amount of opposingtorque between the flyers and the bobbins, and varying the speed of thebobbins in response to any variations sensed in the torque relative tothe opposing torque so applied.

5. A method of controlling the winding speed and lay speed in a rovingframe having rotating flyers for traversing roving onto relativelyrotating and axially reciprocating bobbins which comprises sensing atleast a measure of the torque between the flyers and the bobbins, andproducing relative changes in the relative speed between the flyers andthe bobbins in response to variations in the torque so sensed whileproducing relative changes in the lay speed in direct proportion to therelative changes in the relative speed between the flyers and thebobbins.

6. A method of controlling the winding speed and lay speed in a rovingframe having rotating flyers for traversing roving onto relativelyrotating and axially reciproeating bobbins which comprises sensing atleast a measure of the torque between the flyers and the bobbins, andproducing relative changes in the speed of the bobbins in response tovariations in the torque so sensed while producing relative changes inthe lay speed at progressively changing proportions to the relativechanges in the speed of the bobbins.

7. A method of controlling the winding speed and lay speed in a rovingframe having rotating flyers for traversing roving onto relativelyrotating bobbins which comprises sensing at least a measure of thetorque between the flyers and the bobbins, and varying the speed of thebobbins in response to variations in the torque so sensed while varyingthe lay speed in response to the varying speed of the bobbins and indirect proportion to variations in the bobbin speed.

8. A method of controlling the winding speed and lay speed in a rovingframe having rotating flyers for traversing roving onto relativelyrotating bobbins which comprises sensing at least a measure of thetorque between the flyers and the bobbins, and varying the relativespeed of the flyers and the bobbins in response to variations in thetorque so sensed while varying the lay speed in response to the varyingrelative speed of the flyers and the bobbins but at progressivelychanging proportions with respect to the variations in the relativespeed of the flyers and the bobbins.

9. A method of controlling the winding speed and the lay speed in aroving frame having constant speed rotating flyers for traversing rovingonto axially reciprocating and variable speed rotating bobbins whichcomprises sensing at least a measure of the torque transmitted from therotating bobbins through the roving to the flyers, progressivelyproducing relative changes in the speed of the bobbins in response torelative changes in the torque so sensed, and producing relative changesin the lay speed in direct proportion to the relative changes in thebobbin speed.

10. A method of controlling the winding speed and the lay speed in aroving frame having constant speed rotating flyers for traversing rovingonto axially reciproeating and variable speed rotating bobbins whichcomprises sensing at least a measure of the torque transmitted from therotating bobbins through the roving to the flyers, progressivelyproducing relative changes in the speed of the bobbins in response torelative changes in the torque so sensed, and producing relative changesin the lay speed at a predetermined ratio to the relative changes in thebobbin speed.

11. A method of controlling the winding speed in a roving frame havingrotating flyers for traversing roving onto rotating bobbins whichcomprises sensing at least a measure of the power transmitted betweenthe flyers and the bobbins, and varying the relative speed of the flyersand the bob-bins in response to variations in the power so sensed.

12. Apparatus for producing a constant winding tension in a strand ofroving passing from drafting rolls through a flyer to a bobbincomprising mean to drive the fiver, means operatively associated withthe ilyer driving means for driving said bobbin at a variable speed,means to control the bobbin driving means including means for sensing atleast a measure of the relative changes in the torque transmitted fromthe bobbin through the strand to the flyer, and means to vary the speedof the bobbin driving means in response to the sensed relative changesin the torque so transmitted.

13. In a roving frame having driven drafting rolls and flyers whereinroving passes from the drafting rolls and through the flyers,variable-speed rotating bobbins for receiving roving from the flyers,and driving connections between the bobbins and the flyers; means formaintaining the peripheral speed of the bobbins and roving wound thereonat a speed producing a predetermined constant winding tension in theroving between the flyers and the bobbins comprising a power measuringdevice interposed in the drive connections between the livers and thebobbins, and means responsive to any variation in the power measured bysaid device for compensatively regulating the variable speed of thebobbins to maintain said power constant.

14. In a structure according to claim 13 having a traverse motion forraising and lowering said bobbins relative to said flyers; means fordriving said traverse motion, and means for progressively changing thespeed of said traverse motion in direct proportion to the changes in thespeed of the bobbins effected by said power measuring device.

15. In a structure according to claim 13 having a traverse motion forraising and lowering said bobbins relative to said flyers progressivelydecreasing distances; means for driving said traverse motion, and meansproducing successive relative changes in the speed of the traversemotion at a predetermined ratio with respect to successive relativechanges effected in the speed of the bobbins by said power measuringdevice.

16. In a roving frame having constant-speed driven drafting rolls andflyers wherein roving passes from the drafting rolls and through theflyers, variable-speed rotating bobbins for receiving roving from theflyers, means for maintaining the peripheral speed of the bobbins androving wound thereon at a speed producing a predetermined windingtension in the roving between the flyers and the bobbins comprising avariable speed drive mechanically interconnecting the flyers and thebobbins, and means maintaining a constant predetermined torque balancebetween the input of the variable speed drive and the flyers, saidlast-named means serving to adjust the output speed of the variablespeed drive in accordance with changes in the amount of torque betweenthe flyers and bobbins resulting from variations in the roving and theincreasing diameter of the mass of roving wound on the bobbins.

17. Apparatus for producing a constant winding tension in each of aplurality of strands of roving passing from drafting rolls, throughconstant-speed rotating flyers to variable-speed rotating bobbins in aroving frame, said roving frame including a constant-speed main shaft,21 variable-speed shaft, a compound having two input elements forreceiving power from the main. shaft and said variable speed shaft, andsaid compound having a variable output element for driving said bobbins;the combination therewith of a variable speed drive having an inputshaft and an output portion connected to said variable speed shaft, anauxiliary shaft driven in direct relation with said main shaft, a torquesensing device interposed between said auxiliary shaft and the inputshaft of said variable speed drive, pressure means applying apredetermined balancing torque to said sensing device, and said deviceincluding means responsive to variation sensed in the torque between theauxiliary shaft and the input shaft relative to said balancing torquefor regulating said drive to change the speed of the variable speedshaft and to balance the torque between said auX- iliary shaft and saidinput shaft with said pressure means.

18. Apparatus according to claim 17 wherein said roving frame includes atraverse motion for transmitting vertical reciprocation to said bobbinsrelative to the flyers, and means operatively associated with saidsensing device for driving the traverse motion at relatively changingspeeds at a predetermined ratio to the relative changes in the speed ofthe variable speed shaft.

19. Apparatus according to claim 17 wherein said roving frame includes atraverse motion for transmitting vertical reciprocation to said bobbinsrelative to the flyers, and means operatively associated with saidsensing device for driving the traverse motion at relatively changingspeeds in direct relation to relative changes in the speed of thevariable speed shaft.

20. A structure according to claim 19 wherein said last-named meanscomprises a second variable speed drive having a second input portionand a second output portion, said auxiliary shaft being connected to thesecond input portion, said second output portion being connected indirect driving relation with said traverse motion, and the responsivemeans of said device being operable to regulate the second variablespeed drive in direct relation to its regulation of said first-namedvariable speed drive.

21. In a roving frame having a plurality of rotating flyers andrespective relatively rotating bobbins to which roving is directed bythe flyers, first means to drive said flyers at a constant speed, a topcone shaft driven in direct relation to said flyers, a compounddifferential having a first constant-speed input element driven indirect relation to said flyers and a second variable-speed input elementand an output element, and mechanical connections between the outputelement and the bobbins for varying the speed thereof; the combinationof a variable speed shaft for driving the second input element, avariable speed drive connecting said variable speed shaft with said topcone shaft, a torque sensing device interposed between said top coneshaft and said variable speed drive, said device including meansresponsive to variations in torque between said top cone shaft and saidvariable speed shaft for regulating said variable speed drive to changethe speed of the variable speed shaft and thereby maintain apredetermined constant torque between the top cone shaft and thevariable speed shaft.

22. Apparatus for producing a constant winding tension in each of aplurality of strands of roving passing from drafting rolls, throughconstant-speed rotating flyers to variable-speed rotating bobbins in aroving frame, said roving frame including a constant-speed main shaft,means transmitting rotation from the main shaft to the flyers, a bobbindrive shaft, and means transmitting rotation from the bobbin drive shaftto the bobbins; said apparatus comprising an auxiliary shaft driven indirect relation with said main shaft, a variable speed drive having aconstant-speed input portion and a variable speed output portion, meansconnecting the output portion to said bobbin drive shaft, a torquesensing device interposed between said auxiliary shaft and the inputportion of said variable speed drive, means applying a predeterminedtorque to said sensing device, and means responsive to variation in thetorque between the auxiliary shaft and the input portion of saidvariable speed drive either side of said predetermined torque forregulating said drive to change the speed of the bobbin drive shaft andto balance the torque between said auxiliary shaft and said input shaftwith said predetermined torque.

23. Apparatus for producing a constant winding tension in each of aplurality of strands of roving passing from drafting rolls throughconstant-speed rotating flyers to variable-speed rotating bobbins in aroving frame, said roving frame including a constant-speed main shaft,direct driving connections between the main shaft, the drafting rollsand the flyers, and a compound interposed between the main shaft and thebobbins and having a variable speed input element; the combinationtherewith of a speed variator having a variable speed output portion anda constant speed input shaft, means connecting said variable speedoutput portion to said input element, an auxiliary shaft driven indirect relation with said main shaft, a torque sensing device interposedbetween said auxiliary shaft and the input shaft of said speed variator,means applying a predetermined opposing torque to said sensing device,and said device including means responsive to variation in the torquebetween the auxiliary shaft and the input shaft of said speed variator,either side of the applied torque, for regulating said variator tochange the speed of the variable speed output portion and to balance thetorque between said auxiliary shaft and said input shaft with theapplied torque.

24. A structure according to claim 23 in which said torque sensingdevice comprises a pair of gears fixed on the proximal ends of theauxiliary and input shafts, a housing journaled adjacent the proximalends of said auxiliary and input shafts, a planetary gear disposedbetween and engaging said first-named gears and journaled in saidhousing, and said means applying a predetermined torque beingoperatively associated with said housing and applying said torque in adirection opposite from the direction of rotation of said auxiliaryshaft.

25. A structure according to claim 24 wherein said torque applying meanscomprises a pliable member attached to and at least partially encirclingsaid housing, and a pressure member attached to said pliable element.

26 A structure according to claim 25 in which said pressure member is aWeight and the torque produced by said weight is approximately twice thetorque transmitted through the auxiliary and input shafts.

27. Apparatus for producing a constant winding tension in each of aplurality of strands of roving passing from drafting rolls throughconstant-speed rotating flyers to variable speed rotating bobbins in aroving frame, said roving frame including a constant-speed main shaft,direct driving connections between the main shaft, the drafting rollsand the flyers, and a compound interposed between the main shaft and thebobbins and having a variable speed input element; the combinationtherewith of a speed variator having a variable-speed output portion anda constant-speed input shaft, driving connections between said outputportion and said input element, an auxiliary shaft, direct drivingconnections between the main shaft and the auxiliary shaft, meansmaintaining a constant predetermined torque in the auxiliary shaft andthe input shaft comprising a housing journaled adjacent the proximalends of the auxiliary and input shafts, a planetary gear journaled insaid housing, a pair of sun gears on the proximal ends of said auxiliaryand input shafts and engaging said planetary gear, means applying apredetermined opposing torque to said housing relative to said auxiliaryshaft and causing said housing to rotate upon variation in the torque inthe auxiliary and input shafts, and means responsive to rotation of thehousing for regulating the speed of the output portion of the 2% speedvariator to return the auxiliary and input shafts to balanced conditionrelative to the opposing torque applied to said housing.

28. A structure according to claim 27 including a braking deviceassociated with said housing, and means rendering said braking deviceeffective to lock said housing against rotation when the torque in saidauxiliary and input shafts is less than the opposing torque applied bysaid torque applying means.

29. In a structure according to claim 27, means for resetting the torquemaintaining means, comprising auxiliary means for driving said auxiliaryshaft at a relatively slow speed independently of said main shaftwhereby the torque between said auxiliary and input shafts issubstantially less than said opposing torque and whereby said opposingtorque imparts reverse rotation to said housing.

30. A structure according to claim 29 including mechanical connectionsbetween the housing and the input shaft of the speed variator forlimiting the extent of rotative speed imparted to said housing by saidopposing torque during the resetting operation, and overriding clutchmeans in said last-named mechanical connections being so arranged thatsaid input shaft may rotate at a relatively fast operating speed withoutimparting rotation to said housing.

31. A structure according to claim 29 including a braking device forlocking said housing against rotation during intervals in which theroving frame is not operating, and means for releasing said brakingmeans during intervals of operation of said auxiliary means for drivingsaid auxiliary shaft.

32. A structure according to claim 31 in which said roving frame isequipped with means for starting rotation of said main shaft, and meansfor delaying the releasing of said braking means for a predeterminedinterval following the starting of said main shaft.

33. A structure according to claim 27 wherein said means for regulatingthe speed of the output portion of the speed variator comprises acontrol shaft connected to the speed variator, and gear means connectingthe housing to said control shaft whereby rotation of the housingimparts rotation to the control shaft.

34. A structure according to claim 33 wherein said roving frame includesa traverse motion, a second speed variator having an input portionconnected to said auxiliary shaft and a second variable speed outletportion connected to said traverse motion, and said control shaft beingoperatively connected to said second speed variator for regulating thesame in direct relation to regulation of said first-named speedvariator.

35. A structure according to claim 33 wherein said roving frame includesa traverse motion, a second speed variator having an input portionconnected to said auxiliary shaft and a second variable speed outletportion connected to said traverse motion, means connecting said controlshaft to said second speed variator comprising a second control shaftfor regulating the speed of the second variator, and means fortransmitting rotation from the first-named control shaft to the secondcontrol shaft at a different speed than that of the first-named controlshaft.

36. A structure according to claim 35 wherein said last-named meanscomprises a speed-reducing gear train.

37. Apparatus for producing a constant stretch factor and constantwinding tension in each of a plurality of strands of roving passing fromfront bottom drafting rolls, through constant-speed rotating flyers tovariable-speed rotating bobbins in a roving frame, said roving frameincluding a constant-speed main shaft, means transmitting rotation fromthe main shaft to the flyers, a bobbin drive shaft, and meanstransmitting rotation from the bobbin drive shaft to the bobbins; saidapparatus comprising an auxiliary shaft driven in direct relation withsaid main shaft, a speed variator having a constant speed input shaftand a variable speed output portion, means connecting the output portionto said bobbin drive shaft, a torque measuring device interposed betweensaid auxiliary shaft and the input portion of said variable speed drive,said measuring device comprising a housing journaled adjacent proximalends of said auxiliary and input shafts, a planetary gear journaled inthe housing, a pair of sun gears on proximal ends of the auxiliary andinput shafts, means for applying to said housing a given torque equal tothe product derived from multiplication of the transmission ratio fromthe auxiliary shaft to the front bottom drafting rolls times the Windingtension in grams times the diameter of the front bottom rolls in inchestimes the number of bobbins on the roving frame times the stretchfactor, said torque being applied to said housing in the oppositedirection from that of rotation of said auxiliary shaft, whereby saidtorque applying means rotates said housing upon the torque in saidauxiliary and input shafts varying relative to said given torque, andmeans responsive to rotation of said housing for regulating said driveto change the speed of the bobbin drive shaft and to balance the torquein said auxiliary and input shafts with said given torque.

38. Apparatus for producing a constant winding tension in each of aplurality of strands of roving passing from drafting rolls throughrotating flyers to rotating bobbins in a roving frame, said roving frameincluding a main shaft, first electrical means for starting andmaintaining rotation of said shaft, direct driving connections betweenthe main shaft, the drafting roHs and the flyers, and a compoundinterposed between the main shaft and the bobbins and having a variablespeed input element; the combination therewith of a speed variatorhaving a variable output and a constant input shaft, driving connectionsbetween said output and said input element, an auxiliary shaft, directdriving connections between the main and the auxiliary shafts, meansmaintaining a constant predetermined torque between the auxiliary andinput shafts comprising a housing journaled on the proximal ends in theauxiliary and input shafts, a planetary gear journaled in said housing,a pair of sun gears on the proximal ends of said auxiliary and inputshafts and engaging said planetary gear, means applying a predeterminedopposing torque to said housing relative to said auxiliary shaft andcausing said housing to rotate upon variation in the torque in theauxiliary and input shafts, means responsive to rotation of the housingfor regulating the speed of the output of the speed variator to returnthe auxiliary and input shafts to balanced condition relative to theopposing torque applied to said housing, an electrically deactivatedbraking device for said housing located in a parallel electrical circuitto said first electrical means, and means actuating said device to brakesaid housing when the circuit to said first electrical means is open.

39. A structure according to claim 38 including means to delaydeactivation of said braking device upon initial energization of saidfirst electrical means substantially until said main shaft reaches saidconstant speed.

40. A structure according to claim 38 including means to delaydeactivation of said braking device for a predetermined intervalfollowing initial energization of said first electrical means.

41. A structure according to claim 38 wherein said first electricalmeans comprises an electric motor, a timedelay-relay having a switchthereon interposed in the electrical circuit to said braking device, butbeing disposed in parallel with said electric motor, and saidtimedelay-relay being operable to close the circuit to the brakingdevice and deactivate the same a predetermined interval after theclosing of the electrical circuit to said electric motor.

42. A structure according to claim 41 including a second electric motor,means connecting the second electric motor with said auxiliary shaft, anoverriding clutch means whereby said auxiliary shaft may be rotated bythe sec- 0nd electric motor at a slower speed than the speed irnpartedthereto by said main shaft, said second electric motor being arranged insaid circuit parallel with said first electric motor and in series withsaid electrically deactivated braking device for deactivating thebraking device during energization of the second electric motor, andsaid second electric motor being adapted to drive said auxiliary shaftat a relatively slow speed whereby the opposing torque effected by saidtorque applying means imparts reverse rotation to said housing forresetting said housing while the main shaft is stopped.

43. A structure according to claim 42 including means operableautomatically upon completion of the resetting of said housing forbreaking the circuit to the auxiliary motor.

44. In a roving frame having driven drafting rolls and flyers whereinroving passes from the drafting rolls and through the flyers,variable-speed rotating bobbins for receiving roving from the flyers, avertically reciprocating carriage for the bobbins, a traverse motion forimparting reciprocating movement to the carriage; means for driving saidtraverse motion comprising a speed variator mechanically interconnectingthe flyers and the traverse motion, means for sensing a torqueproportional to the torque transmitted from the bobbins through theroving to the flyers, and means responsive to said sensing means toadjust the output speed of the speed variator in direct rela tion torelative changes in the torque so sensed.

45. In a roving frame having constant-speed driven drafting rolls andflyers wherein roving passes from the drafting rolls and through theflyers, variable-speed rotating bobbins for receiving roving from theflyers, a vertically reciprocating carriage for the bobbins, and atraverse motion for imparting reciprocating movement to the carriage;means for driving said traverse motion comprising a speed variatormechanically interconnecting the flyers and the traverse motion, meansfor sensing at least a measure of the torque transmitted from thebobbins through the roving to the flyers, and means responsive to saidsensing means to adjust the output speed of the speed variator at apredetermined ratio to relative changes in the torque so sensed.

46. In a roving frame having constant speed driven drafting rolls andflyers wherein roving passes from the drafting rolls and through theflyers, rotating bobbins for receiving roving from the flyers, a mainshaft for driving said flyers, means for transmitting rotation from themain shaft to the bobbins at progressively decreasing speeds ofpredetermined relatively changing relationship, a verticallyreciprocating carriage for said bobbins, and a traverse motion fortransmitting vertical reciprocatory movement to said carriage; thecombination of a speed variator interposed between said main shaft andsaid traverse motion, means for sensing at least a measure of anyvariation in torque between the main shaft and the bobbins, and meansautomatically operable in response to variation in the torque so sensedfor regulating said variator to produce relative changes in the speed ofthe traverse mo tion which differ from the relative changes in the speedof the bobbins.

47. Apparatus for producing constant winding tension in textile strandspassing from drafting rolls through rotating flyers and rotating bobbinscomprising: means for drving said flyers and bobbins at relative speeds,means for sensing at least a measure of any relative changes in thetorque transmitted between the flyers and the bobbins, and meanscontrolling said drive means to vary the relative speed between saidflyers and said bobbins in response to the sensed relative changes inthe torque so transmitted.

References Cited in the file of this patent UNITED STATES PATENTS2,901,882 Granberry Sept. 1, 1959 2,901,883 Granberry Sept. 1, 19592,925,704 Noda Feb. 23, 1960

